Prevent "control reaches end of non-void function" warning from gcc on Mac.

src/runtime.cc

 // Copyright 2006-2009 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 4953 matching lines @@
   ASSERT(month >= 0);
   ASSERT(month < 12);
 
   static const int base_day = 365*1969 + 1969/4 - 1969/100 + 1969/400;
   int year1 = year - 1;
   int day_from_year = 365 * year1 + year1 / 4 - year1 / 100 + year1 / 400 -
                       base_day;
 
   if (year % 4 || (year % 100 == 0 && year % 400 != 0)) {
     return Smi::FromInt(day_from_year + day_from_month[month] + date - 1);
-  } else {
-    return Smi::FromInt(day_from_year + day_from_month_leap[month] + date - 1);
   }
+
+  return Smi::FromInt(day_from_year + day_from_month_leap[month] + date - 1);
 }
 
 
 static Object* Runtime_NewArgumentsFast(Arguments args) {
   NoHandleAllocation ha;
   ASSERT(args.length() == 3);
 
   JSFunction* callee = JSFunction::cast(args[0]);
   Object** parameters = reinterpret_cast<Object**>(args[1]);
   const int length = Smi::cast(args[2])->value();
@@ skipping 3407 matching lines @@
   } else {
     // Handle last resort GC and make sure to allow future allocations
     // to grow the heap without causing GCs (if possible).
     Counters::gc_last_resort_from_js.Increment();
     Heap::CollectAllGarbage(false);
   }
 }
 
 
 } }  // namespace v8::internal